1. Field of the Invention
The present invention relates to a method and an apparatus for stably controlling an ignition operation of a gas boiler regardless of external conditions by means of a method and an apparatus for variably setting an ignition condition of the gas boiler.
2. Description of the Prior Art
In general, a gas boiler which uses gas as fuel heats water using the high temperature generated by the burning gas. The heated water circulates through heating pipes disposed inside a room and produces heat inside the room. The gas which is used as fuel of the gas boiler is burned completely. Consequently, the gas boiler is safe due to the absence of environmental pollution, and is gradually and widely used due to its convenience of use.
FIG. 1 is a configuration view for showing the configuration of a conventional gas boiler.
Referred to FIG. 1, generally, the gas boiler comprises a gas valve 10, a burner 12, a flame voltage detector 14, an ignition plug 16, a ventilation hood 18, a heat exchanger 20, a ventilation fan 22, a circulation pump 26, and a water tank 28.
When a user sets the gas boiler in an operation mode, the gas is supplied to burner 12 through gas valve 10 by a predetermined amount. A high voltage is applied to ignition plug 16 by a microcomputer (not shown) in order to ignite the gas which is supplied to burner 12. When a spark for the ignition is generated from ignition plug 16 due to the high voltage, the gas supplied to burner 12 is ignited and the gas boiler executes a combustion operation.
At this time, flame voltage detector 14 detects a flame voltage value which is generated by a blaze of an ignited state, and provides the detected flame voltage value to the microcomputer. The microcomputer judges whether or not the gas boiler is in an ignition state based on a comparison between the detected flame voltage value and a predetermined ignition flame voltage value. When the gas boiler is in an ignition state, the microcomputer executes a normal combustion operation of the gas boiler, and when the gas boiler is not in an ignition state, the microcomputer executes a re-ignition operation of the gas boiler.
However, in the above-described prior gas boiler, ignition failures frequently occur. Especially, since the components which consist of the gas boiler are different from each other in their characteristics, when the characteristics of the components, e.g., flame voltage detector 14 etc., change while using the gas boiler for a long time, flame voltage detector 14 cannot normally detect the flame voltage value in an ignition state, a combustion state and an extinguishment state of the gas boiler.
Also, in the case where combustion gas is not normally exhausted by an adverse wind which flows into the inside of the gas boiler from the outside through ventilation hood 18 while the ignition operation is being executed, or in the case where the flame is blown by a favorable wind which is supplied to a lower part of burner 12, flame voltage detector 14 cannot accurately detect the flame voltage value.
As a result, although the gas boiler is actually ignited, the microcomputer judges that the gas boiler is not ignited based on an abnormally-detected flame voltage value and repeatedly executes the re-ignition operation of the gas boiler.